Month: April 2015

I don’t care that the earth’s shadow eclipses the moon, said the Admiral. I have seen terrific irregularity with mine own eyes, and have been forced to the sensible conclusion that this earth is not round as some wrongly insist, but the shape of a pear or violin.

A thousand years before the Admiral made his daring proclamation and charted his course on this violin-shaped earth, people thought it was flat like a discus. Until the Greek Cartographer spoke out, claiming it was round like an orange. He’d drawn standard aesthetic divisions on his planisphere, a flattened version of his rounded earth. The first set of lines he called “latitude.” But his finest moment, his greatest act of self-control, had been to leave parts of his map blank. The Cartographer was later forgotten, his map lost like dreams that are lost upon waking, lingering only as faint unglimpsable residues. Seafarers…

A late-night encounter with a drunken classmate is at the beginning of many college sexual assault stories. But in the one Gracie Ryan tells, the woman—a third-degree taekwondo black belt—feels uncomfortable, gets up, and leaves. “Even if a girl is scared to death,” she tells Ryan, “if she walks into a room tall and confident, it’s like, don’t fuck with me.” Ryan’s article checks in on the progress of various sexual assault prevention programs offered at the University of Montana following federal investigations into mishandling of reports of sexual violence in 2012. Students formed self-defense classes. The university requires students living in dorms to undergo bystander-intervention training. Ryan checks in on each program and pairs text and photos to chronicle a university and its students trying lots of different ways, with varying success, to solve a problem that plagues too many campuses.

According to a recent study, head-mounted, compass-like devices connected to the brains of blind rats have allowed them to navigate a maze almost as well as normal-sighted rats. Researchers indicate that a similar technique could be used to help blind humans navigate. The researchers, Yuji Ikegaya and Hiroaki Norimoto of the University of Tokyo, pubished the details of their creation in the journal Current Biology. Approximately 39 million people around the world are blind, 82% of whom are 50 or older. Blindness interferes not only with vision, but also spatial awareness (“allocentric sense”), or a person’s ability to recognize the position of their body relative to their surroundings.

For their study, the researchers set out to see if they could restore allocentric sense of “blind” adult rats by stimulating the visual cortex in their brains. They created a lightweight head-mountable sensor device made up of a digital compass (the same as those found in smartphones) connected to a microstimulator with two electrodes. Once implanted into the visual cortex of the animals’ brains, the device was able to detect their head movements and generate an electrical stimulation, or “geomagnetic signal”, informing the animals which direction they were facing.

The researchers set out to test whether the device could guide the blind rats through a maze, effectively restoring their allocentric sense. With the devices attached, the rats were trained to seek food pellets in the T-shaped maze, as well as more complicated maze shapes. Their ability to solve each maze was compared with that of normal-sighted rats, who could depend on visual cues to reach the food pellets. Ikegaya and Norimoto found that within 2-3 days of maze training, the blind rats learned to use the geomagnetic signal triggered by the device to find the food pellets. The researchers say that these findings demonstrate just how the mammalian brain is able to learn and adapt to new information well into adulthood.

From their research, the team believes that the findings could be applied to humans, with geomagnetic sensors being attached to the walking sticks of blind people to help them navigate their surroundings. The researchers say that a geomagnetic sensor device similar to the one used in their study may be effective for restoring allocentric sense in blind people, and that artificial sensors could even be used to detect ultraviolet radiation and ultrasound waves.

Many of the stars in the Universe live with companions by their sides in so-called “binary systems”. In these binary systems, two stars orbit around their common center of gravity. Suitable binary systems are extremely important in astrophysics, since their properties can be inferred with unparalleled accuracy from detailed analysis of their orbital properties. Oddly enough, however, a huge majority of the known members of the RR Lyrae variable star family have lived their lives alone. These stars, the oldest known stars in the cosmos, contain vital information about the origin and evolution of the stellar systems that host them, including the Milky Way itself. However, a lack of RR Lyrae stars in binary systems has made directly assessing some of their key properties extremely difficult, and theory frequently has to be invoked to fill the gap.

The solitude of these stars has always puzzled astronomers. Now, however, an international research team led by the Millennium Institute of Astrophysics (MAS) and the Pontificia Universidad Catolica de Chile’s Institute of Astrophysics (IA-PUC) have discovered that these stars may not hate companionship as much as previously thought. The team reported on identification of as many as 20 candidate binaries for RR Lyrae, an increase of up to 2000% from previous tallies. Twelve of these candidates have enough measurements to conclude that they do indeed consist of two stars orbiting each other. In their paper, the authors used a method that astronomers call the “light-travel time effect”, which exploits subtle differences in time that it takes starlight to reach us. The RR Lyrae stars pulsate regularly, significantly increasing and then decreasing their sizes, temperatures and brightness in just a few hours. When a pulsating star is in a binary system, the changes in brightness that we perceive can be affected by where the star is in the course of its orbit around the companion. This means that starlight takes longer to reach us when it’s at the farthest point along its orbit, and vice-versa.

The researchers’ measurements were based on data published by the Polish OGLE Project, who has obtained their data using the 1.3m Warsaw telescope in Las Campanas Observatory in northern Chile, repeatedly observing the same patches of the sky for many years. The 20 binary candidates were found analyzing the roughly 2000 best observed RR Lyrae stars towards the central parts of the Milky Way, making up about 5% of the known ones. Only thanks to the high quality of the OGLE data and long timespan of these observations that the researchers could finally find signs of companions around so many of these stars.

Indeed, the systems detected by researchers have orbital periods of several years, indicating that the companions aren’t very close to one another, even though they’re bound together by gravity. Binaries with even longer periods could also exist, but the current data doesn’t extend long enough for researchers to reach strong conclusions about them. The researchers have pointed out that these results have significant implications for astrophysics; these are extremely old stars that have witnessed the formation of galaxies. They’re also easy to identify, since they show characteristic, cyclical brightness variations that make them excellent distance indicators for the nearby Universe. Now, researchers can exploit the orbital information contained in these binary systems in order to directly measure their physical properties, especially their masses but maybe their diameters as well. This could open new doors to discoveries that had previously seemed impossible.